Perkins was served with an indictment in the Selwyn case five days before his scheduled release and was extradited to Los Angeles, where he was tried and convicted of second-degree murder. His sentencing is scheduled for Wednesday in Los Angeles Superior Court.

"It had been almost five years. I didn't tell the family, but I was discouraged about ever solving that case," Andrews said. "We never would have solved (the Selwyn) case except for 'Unsolved Mysteries.' "

The geographical reach of the crime programs was illustrated more dramatically in 1990, when "America's Most Wanted" helped lead police to the murderer of Hollywood resident Barry Glick, a sunglasses salesman.

The killer, Gerald Reeves, reportedly befriended Glick and then robbed and fatally stabbed him in April, 1990, fleeing to Modesto in Glick's car, said LAPD homicide Detective Dennis Kilcoyne. In Modesto, Reeves committed a robbery and kidnaping and successfully eluded police--until Kilcoyne asked "America's Most Wanted" to profile the Glick murder.

After the program aired, police were inundated with 350 telephone tips indicating that Reeves had traveled across the country, befriending and robbing women and gay men in half a dozen states.

When the show profiled Reeves a second time in December, a Maryland woman called in and said she had just spoken to Reeves, who was planning to spend Christmas with her daughter. Reeves was visiting the Circus Circus casino and hotel in Reno, she said--a fact confirmed by other "America's Most Wanted" callers who said they had seen him in the casino that night.

The next morning, Reeves was captured in a Western Union office where police had lured him with a phony money transfer. In 1992, he was convicted of murder in Los Angeles and is now serving a sentence of life without parole, Kilcoyne said.

Such results have caught the attention of local law enforcement agencies, who now work closely with crime shows that many were skeptical about when such programming began in the late 1980s.

Tim Rogan, coordinating producer of "Unsolved Mysteries," estimates that his weekly show garners a few thousand calls during or immediately after each program airs. And with shows rerunning in syndication, that can add up to about 10,000 tips a week, he said.

Despite the massive number of tips, it has taken the shows some time to prove their worth to police, Zanelotti said.

"When we started the show, law enforcement agencies were suspicious of what we wanted to do, and what we could do for them," he said.

Not so now. Said Brant of "America's Most Wanted": "Some (police) call us the day after a crime occurs."

These days, in fact, police are practically part of the production crew. After successfully lobbying "America's Most Wanted" to profile the slaying of Plese, the Brink's guard, Linehan of the Beverly Hills Police Department appeared on televised interviews and voice-overs for the program. He and his partner, Detective Michael Hopkins, were flown to the show's headquarters in Washington for its airing on Nov. 12.

There, they were stationed at a 30-line telephone bank. Operators connected them with callers who appeared to have promising leads and took down other callers' information that the police could study later, Linehan said.

After the show aired, 60 calls came in. Linehan declined to discuss any prospective clues. But he says that one of the calls was from Plese's half-brother, who first learned from the TV show that his sibling had been killed.

Crime show producers say there is no guarantee that their programs will produce clues. Indeed, many cases profiled on crime shows have yet to be resolved--among them, the disappearance of Adam Hecht, a 24-year-old tennis instructor who vanished from his Beverly Hills apartment in June, 1989.

Hecht's rental car was found abandoned in Beverly Hills with his wallet, containing cash and credit cards, inside the vehicle.

Before his disappearance, police say, Hecht had expressed interest in being among homeless people and helping them. They speculate that he may have dropped out of sight to become a street person.

Hecht's family successfully lobbied "Unsolved Mysteries" to profile the case, but so far the broadcasts have failed to help explain his disappearance.

"We're not giving up hope," said Beverly Hills Police Lt. Frank Salicido. "In the case of a missing person, you never know where they might be."